Coccidioides immitis is a fungal pathogen of humans that causes a respiratory disease called Valley Fever. There are an estimated 100,000 new cases of Valley Fever in the southwestern United States each year, but the disease is also found in parts of Central and South America. Most infections resolve spontaneously, but 5 percent of individuals develop severe disseminated disease. Long-term chemotherapy, with many adverse side effects, is required in cases of severe disease. No vaccine is currently available. To facilitate basic research and to stimulate the development of drugs and vaccines, we intend to obtain the sequence of the 28 Mb C. immitis C735 genome over a 2-year period through completion of these Specific Aims: 1) Determination of greater than 99 percent of the genome sequence using a whole genome shotgun strategy (8X coverage and closure of 1 Mb); 2) Annotation and analysis of the genome sequence; 3) Mapping of groups of linked contigs to the four chromosomes; 4) Generation of 30,000 Expressed Sequence Tags (ESTs) and a C. immitis Gene Index; 5) Pilot studies of gene expression in the saprobic and parasitic phases of the life cycle using glass slide microarrays of ESTs and genomic PCR products. Successful completion of this project will provide an invaluable resource for investigators studying C. immitis and other fungal pathogens.